wasm compilation not working

[ncitron]

Version
1.0.0

Description
WASM compilation currently only works if you compile the example in examples/ethers-wasm while its still inside the main ethers-rs repo. If you copy the entire contents of the folder somewhere else, compilation will fail with dozens of errors relating to the meo crate (I think it is a dependency of tokio). It seems that any crate the imports ethers-rs fails this way when compiling to wasm in my testing.

Here is what the errors look like: https://pastebin.com/BwcEi9Zk

[mattsse]

for some reason tokio is pulled in if you directly depend on ethers.

however I've checked all default features and tokio usage in all subcrates which should be ignored for the wasm target, however iirc there are some issues with mutually exclusive cfg(condition) and cfg(not(condition)) cfgs, which could be relevant here.

[slumber]

This is still reproducible if you have ethers-wasm as a workspace member. I.e. create folder with the following Cargo.toml:

[workspace]
members = ["ethers-wasm"]

And then try to

cargo build -p ethers-wasm --target wasm32-unknown-unknown

This will try to compile ~70 additional targets and in the end produces the same huge list of errors related to mio.

Probably caused by https://nickb.dev/blog/cargo-workspace-and-the-feature-unification-pitfall/

[QYuQianchen]

Running into the similar issue here. Our project has one crate for smart contracts where it contains foundry-generated contract bindings, and another crate which uses those bindings and compiles to wasm with wasm-bindgen. The same sets of errors related to mio are reported when running cargo build.

[slumber]

Running into the similar issue here. Our project has one crate for smart contracts where it contains foundry-generated contract bindings, and another crate which uses those bindings and compiles to wasm with wasm-bindgen. The same sets of errors related to mio are reported when running cargo build.

As a workaround you can move wasm crate into a subworkspace via adding

[workspace]
# nothing here

to the bottom of its Cargo.toml.